| 摘要 |
PURPOSE:To prevent generation of superfluous flow and to lower the energy loss of a variable displacement type pump, by imparting a regulator with a function fo reducing inclination of the pump when the discharge pressure of the pump has reached a predetermind level, so that the pump discharge fluid just at the rate capable of maintaining said predetermined pressure. CONSTITUTION:When discharge pressure Pd becomes lower than a setting pressure of a changeover valve 61 along with decreasing of fluid flow discharged from the pump, a spool 94 of the changeover valve 61 is moved to the right by the force of a spring, so that passages 102 and 64 are communicated to each other. Resultantly, servo pressure Ps is transmitted to a right liquid chamber 73 and a servo piston 74 is moved to the left, so that the flow rate of the pump is increased. Subsequently, when the discharge pressure Pd exceeds the setting pressure of the valve 61, the spool 94 is moved to the left against the force of the spring, so that the flow rate is decreased. Therefore, inclination of the pump is kept at an angle capable of affording a flow rate required for maintaining the discharge pressure Pd at the setting pressure of th changeover valve 61. Thus, it is enabled to prevent generation of superfluous flow and to lower the energy loss of the pump. |
